US20030148880A1 - Methanol-decomposing catalyst and methanol-decomposing apparatus comprising same - Google Patents
Methanol-decomposing catalyst and methanol-decomposing apparatus comprising same Download PDFInfo
- Publication number
- US20030148880A1 US20030148880A1 US09/442,761 US44276199A US2003148880A1 US 20030148880 A1 US20030148880 A1 US 20030148880A1 US 44276199 A US44276199 A US 44276199A US 2003148880 A1 US2003148880 A1 US 2003148880A1
- Authority
- US
- United States
- Prior art keywords
- methanol
- decomposing
- catalyst
- ceria
- zinc
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Granted
Links
- 239000003054 catalyst Substances 0.000 title claims abstract description 107
- MCMNRKCIXSYSNV-UHFFFAOYSA-N Zirconium dioxide Chemical compound O=[Zr]=O MCMNRKCIXSYSNV-UHFFFAOYSA-N 0.000 claims abstract description 56
- CETPSERCERDGAM-UHFFFAOYSA-N ceric oxide Chemical compound O=[Ce]=O CETPSERCERDGAM-UHFFFAOYSA-N 0.000 claims abstract description 55
- 229910000422 cerium(IV) oxide Inorganic materials 0.000 claims abstract description 55
- GWEVSGVZZGPLCZ-UHFFFAOYSA-N Titan oxide Chemical compound O=[Ti]=O GWEVSGVZZGPLCZ-UHFFFAOYSA-N 0.000 claims abstract description 50
- RYGMFSIKBFXOCR-UHFFFAOYSA-N Copper Chemical compound [Cu] RYGMFSIKBFXOCR-UHFFFAOYSA-N 0.000 claims abstract description 33
- HCHKCACWOHOZIP-UHFFFAOYSA-N Zinc Chemical compound [Zn] HCHKCACWOHOZIP-UHFFFAOYSA-N 0.000 claims abstract description 33
- 229910052802 copper Inorganic materials 0.000 claims abstract description 33
- 239000010949 copper Substances 0.000 claims abstract description 33
- 229910052725 zinc Inorganic materials 0.000 claims abstract description 33
- 239000011701 zinc Substances 0.000 claims abstract description 33
- 229910052751 metal Inorganic materials 0.000 claims description 11
- 239000002184 metal Substances 0.000 claims description 11
- 150000002739 metals Chemical class 0.000 claims description 5
- 239000000919 ceramic Substances 0.000 claims description 3
- UFHFLCQGNIYNRP-UHFFFAOYSA-N Hydrogen Chemical compound [H][H] UFHFLCQGNIYNRP-UHFFFAOYSA-N 0.000 abstract description 27
- 238000007086 side reaction Methods 0.000 abstract description 8
- 230000003197 catalytic effect Effects 0.000 abstract description 5
- OKKJLVBELUTLKV-UHFFFAOYSA-N Methanol Chemical compound OC OKKJLVBELUTLKV-UHFFFAOYSA-N 0.000 description 133
- 239000007789 gas Substances 0.000 description 18
- 238000006243 chemical reaction Methods 0.000 description 16
- 238000000354 decomposition reaction Methods 0.000 description 15
- 239000001257 hydrogen Substances 0.000 description 14
- 229910052739 hydrogen Inorganic materials 0.000 description 14
- 239000000446 fuel Substances 0.000 description 12
- 239000000203 mixture Substances 0.000 description 12
- 239000000843 powder Substances 0.000 description 10
- XLYOFNOQVPJJNP-UHFFFAOYSA-N water Chemical compound O XLYOFNOQVPJJNP-UHFFFAOYSA-N 0.000 description 9
- RTZKZFJDLAIYFH-UHFFFAOYSA-N Diethyl ether Chemical compound CCOCC RTZKZFJDLAIYFH-UHFFFAOYSA-N 0.000 description 8
- 238000009472 formulation Methods 0.000 description 8
- 239000011521 glass Substances 0.000 description 7
- CURLTUGMZLYLDI-UHFFFAOYSA-N Carbon dioxide Chemical compound O=C=O CURLTUGMZLYLDI-UHFFFAOYSA-N 0.000 description 6
- PNEYBMLMFCGWSK-UHFFFAOYSA-N aluminium oxide Inorganic materials [O-2].[O-2].[O-2].[Al+3].[Al+3] PNEYBMLMFCGWSK-UHFFFAOYSA-N 0.000 description 6
- 239000007864 aqueous solution Substances 0.000 description 6
- VNWKTOKETHGBQD-UHFFFAOYSA-N methane Chemical compound C VNWKTOKETHGBQD-UHFFFAOYSA-N 0.000 description 6
- 239000002245 particle Substances 0.000 description 5
- 239000003208 petroleum Substances 0.000 description 5
- KDLHZDBZIXYQEI-UHFFFAOYSA-N Palladium Chemical compound [Pd] KDLHZDBZIXYQEI-UHFFFAOYSA-N 0.000 description 4
- UIIMBOGNXHQVGW-UHFFFAOYSA-M Sodium bicarbonate Chemical compound [Na+].OC([O-])=O UIIMBOGNXHQVGW-UHFFFAOYSA-M 0.000 description 4
- XLOMVQKBTHCTTD-UHFFFAOYSA-N Zinc monoxide Chemical compound [Zn]=O XLOMVQKBTHCTTD-UHFFFAOYSA-N 0.000 description 4
- 239000006227 byproduct Substances 0.000 description 4
- 239000012018 catalyst precursor Substances 0.000 description 4
- OKTJSMMVPCPJKN-UHFFFAOYSA-N Carbon Chemical compound [C] OKTJSMMVPCPJKN-UHFFFAOYSA-N 0.000 description 3
- HEMHJVSKTPXQMS-UHFFFAOYSA-M Sodium hydroxide Chemical compound [OH-].[Na+] HEMHJVSKTPXQMS-UHFFFAOYSA-M 0.000 description 3
- FMRLDPWIRHBCCC-UHFFFAOYSA-L Zinc carbonate Chemical compound [Zn+2].[O-]C([O-])=O FMRLDPWIRHBCCC-UHFFFAOYSA-L 0.000 description 3
- 229910002092 carbon dioxide Inorganic materials 0.000 description 3
- 239000007795 chemical reaction product Substances 0.000 description 3
- 229940116318 copper carbonate Drugs 0.000 description 3
- GEZOTWYUIKXWOA-UHFFFAOYSA-L copper;carbonate Chemical compound [Cu+2].[O-]C([O-])=O GEZOTWYUIKXWOA-UHFFFAOYSA-L 0.000 description 3
- 238000002474 experimental method Methods 0.000 description 3
- 239000003502 gasoline Substances 0.000 description 3
- 229910002804 graphite Inorganic materials 0.000 description 3
- 239000010439 graphite Substances 0.000 description 3
- 238000010438 heat treatment Methods 0.000 description 3
- 238000004519 manufacturing process Methods 0.000 description 3
- 239000008188 pellet Substances 0.000 description 3
- 239000002002 slurry Substances 0.000 description 3
- 239000011667 zinc carbonate Substances 0.000 description 3
- 235000004416 zinc carbonate Nutrition 0.000 description 3
- 229910000010 zinc carbonate Inorganic materials 0.000 description 3
- UGFAIRIUMAVXCW-UHFFFAOYSA-N Carbon monoxide Chemical compound [O+]#[C-] UGFAIRIUMAVXCW-UHFFFAOYSA-N 0.000 description 2
- QPLDLSVMHZLSFG-UHFFFAOYSA-N Copper oxide Chemical compound [Cu]=O QPLDLSVMHZLSFG-UHFFFAOYSA-N 0.000 description 2
- 239000005751 Copper oxide Substances 0.000 description 2
- LCGLNKUTAGEVQW-UHFFFAOYSA-N Dimethyl ether Chemical compound COC LCGLNKUTAGEVQW-UHFFFAOYSA-N 0.000 description 2
- WSFSSNUMVMOOMR-UHFFFAOYSA-N Formaldehyde Chemical compound O=C WSFSSNUMVMOOMR-UHFFFAOYSA-N 0.000 description 2
- CDBYLPFSWZWCQE-UHFFFAOYSA-L Sodium Carbonate Chemical compound [Na+].[Na+].[O-]C([O-])=O CDBYLPFSWZWCQE-UHFFFAOYSA-L 0.000 description 2
- 239000011230 binding agent Substances 0.000 description 2
- 229910002091 carbon monoxide Inorganic materials 0.000 description 2
- 229910000431 copper oxide Inorganic materials 0.000 description 2
- 238000007599 discharging Methods 0.000 description 2
- 230000000694 effects Effects 0.000 description 2
- 239000011491 glass wool Substances 0.000 description 2
- 238000000034 method Methods 0.000 description 2
- 239000003345 natural gas Substances 0.000 description 2
- 229910000510 noble metal Inorganic materials 0.000 description 2
- 229910052763 palladium Inorganic materials 0.000 description 2
- 239000002243 precursor Substances 0.000 description 2
- 239000011369 resultant mixture Substances 0.000 description 2
- 150000003839 salts Chemical class 0.000 description 2
- 229910000030 sodium bicarbonate Inorganic materials 0.000 description 2
- 239000007787 solid Substances 0.000 description 2
- 239000000243 solution Substances 0.000 description 2
- ONDPHDOFVYQSGI-UHFFFAOYSA-N zinc nitrate Chemical compound [Zn+2].[O-][N+]([O-])=O.[O-][N+]([O-])=O ONDPHDOFVYQSGI-UHFFFAOYSA-N 0.000 description 2
- 239000011787 zinc oxide Substances 0.000 description 2
- BVKZGUZCCUSVTD-UHFFFAOYSA-L Carbonate Chemical compound [O-]C([O-])=O BVKZGUZCCUSVTD-UHFFFAOYSA-L 0.000 description 1
- 229910017518 Cu Zn Inorganic materials 0.000 description 1
- 230000001133 acceleration Effects 0.000 description 1
- 238000003916 acid precipitation Methods 0.000 description 1
- 229910052782 aluminium Inorganic materials 0.000 description 1
- XAGFODPZIPBFFR-UHFFFAOYSA-N aluminium Chemical compound [Al] XAGFODPZIPBFFR-UHFFFAOYSA-N 0.000 description 1
- QVGXLLKOCUKJST-UHFFFAOYSA-N atomic oxygen Chemical compound [O] QVGXLLKOCUKJST-UHFFFAOYSA-N 0.000 description 1
- 239000001569 carbon dioxide Substances 0.000 description 1
- 239000000969 carrier Substances 0.000 description 1
- 150000003841 chloride salts Chemical class 0.000 description 1
- 238000002485 combustion reaction Methods 0.000 description 1
- 230000000052 comparative effect Effects 0.000 description 1
- 150000001875 compounds Chemical class 0.000 description 1
- XTVVROIMIGLXTD-UHFFFAOYSA-N copper(II) nitrate Chemical compound [Cu+2].[O-][N+]([O-])=O.[O-][N+]([O-])=O XTVVROIMIGLXTD-UHFFFAOYSA-N 0.000 description 1
- 229910052593 corundum Inorganic materials 0.000 description 1
- 239000002283 diesel fuel Substances 0.000 description 1
- 238000003487 electrochemical reaction Methods 0.000 description 1
- 230000007613 environmental effect Effects 0.000 description 1
- 150000002170 ethers Chemical class 0.000 description 1
- 230000001747 exhibiting effect Effects 0.000 description 1
- 239000002803 fossil fuel Substances 0.000 description 1
- 159000000011 group IA salts Chemical class 0.000 description 1
- XLYOFNOQVPJJNP-UHFFFAOYSA-M hydroxide Chemical compound [OH-] XLYOFNOQVPJJNP-UHFFFAOYSA-M 0.000 description 1
- 230000003993 interaction Effects 0.000 description 1
- 239000007788 liquid Substances 0.000 description 1
- 238000005259 measurement Methods 0.000 description 1
- 150000002823 nitrates Chemical class 0.000 description 1
- 230000001473 noxious effect Effects 0.000 description 1
- 239000001301 oxygen Substances 0.000 description 1
- 229910052760 oxygen Inorganic materials 0.000 description 1
- 230000035515 penetration Effects 0.000 description 1
- 239000000047 product Substances 0.000 description 1
- 239000012495 reaction gas Substances 0.000 description 1
- 235000017557 sodium bicarbonate Nutrition 0.000 description 1
- 229910000029 sodium carbonate Inorganic materials 0.000 description 1
- 238000004611 spectroscopical analysis Methods 0.000 description 1
- 239000007858 starting material Substances 0.000 description 1
- 238000003756 stirring Methods 0.000 description 1
- 150000003467 sulfuric acid derivatives Chemical class 0.000 description 1
- 238000010792 warming Methods 0.000 description 1
- 229910001845 yogo sapphire Inorganic materials 0.000 description 1
Images
Classifications
-
- B01J35/40—
-
- B—PERFORMING OPERATIONS; TRANSPORTING
- B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
- B01B—BOILING; BOILING APPARATUS ; EVAPORATION; EVAPORATION APPARATUS
- B01B1/00—Boiling; Boiling apparatus for physical or chemical purposes ; Evaporation in general
- B01B1/005—Evaporation for physical or chemical purposes; Evaporation apparatus therefor, e.g. evaporation of liquids for gas phase reactions
-
- B—PERFORMING OPERATIONS; TRANSPORTING
- B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
- B01J—CHEMICAL OR PHYSICAL PROCESSES, e.g. CATALYSIS OR COLLOID CHEMISTRY; THEIR RELEVANT APPARATUS
- B01J23/00—Catalysts comprising metals or metal oxides or hydroxides, not provided for in group B01J21/00
- B01J23/70—Catalysts comprising metals or metal oxides or hydroxides, not provided for in group B01J21/00 of the iron group metals or copper
- B01J23/76—Catalysts comprising metals or metal oxides or hydroxides, not provided for in group B01J21/00 of the iron group metals or copper combined with metals, oxides or hydroxides provided for in groups B01J23/02 - B01J23/36
- B01J23/83—Catalysts comprising metals or metal oxides or hydroxides, not provided for in group B01J21/00 of the iron group metals or copper combined with metals, oxides or hydroxides provided for in groups B01J23/02 - B01J23/36 with rare earths or actinides
-
- B—PERFORMING OPERATIONS; TRANSPORTING
- B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
- B01J—CHEMICAL OR PHYSICAL PROCESSES, e.g. CATALYSIS OR COLLOID CHEMISTRY; THEIR RELEVANT APPARATUS
- B01J37/00—Processes, in general, for preparing catalysts; Processes, in general, for activation of catalysts
- B01J37/02—Impregnation, coating or precipitation
- B01J37/03—Precipitation; Co-precipitation
-
- C—CHEMISTRY; METALLURGY
- C01—INORGANIC CHEMISTRY
- C01B—NON-METALLIC ELEMENTS; COMPOUNDS THEREOF; METALLOIDS OR COMPOUNDS THEREOF NOT COVERED BY SUBCLASS C01C
- C01B3/00—Hydrogen; Gaseous mixtures containing hydrogen; Separation of hydrogen from mixtures containing it; Purification of hydrogen
- C01B3/02—Production of hydrogen or of gaseous mixtures containing a substantial proportion of hydrogen
- C01B3/22—Production of hydrogen or of gaseous mixtures containing a substantial proportion of hydrogen by decomposition of gaseous or liquid organic compounds
-
- B—PERFORMING OPERATIONS; TRANSPORTING
- B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
- B01J—CHEMICAL OR PHYSICAL PROCESSES, e.g. CATALYSIS OR COLLOID CHEMISTRY; THEIR RELEVANT APPARATUS
- B01J21/00—Catalysts comprising the elements, oxides, or hydroxides of magnesium, boron, aluminium, carbon, silicon, titanium, zirconium, or hafnium
- B01J21/06—Silicon, titanium, zirconium or hafnium; Oxides or hydroxides thereof
- B01J21/063—Titanium; Oxides or hydroxides thereof
-
- B—PERFORMING OPERATIONS; TRANSPORTING
- B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
- B01J—CHEMICAL OR PHYSICAL PROCESSES, e.g. CATALYSIS OR COLLOID CHEMISTRY; THEIR RELEVANT APPARATUS
- B01J21/00—Catalysts comprising the elements, oxides, or hydroxides of magnesium, boron, aluminium, carbon, silicon, titanium, zirconium, or hafnium
- B01J21/06—Silicon, titanium, zirconium or hafnium; Oxides or hydroxides thereof
- B01J21/066—Zirconium or hafnium; Oxides or hydroxides thereof
-
- B—PERFORMING OPERATIONS; TRANSPORTING
- B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
- B01J—CHEMICAL OR PHYSICAL PROCESSES, e.g. CATALYSIS OR COLLOID CHEMISTRY; THEIR RELEVANT APPARATUS
- B01J23/00—Catalysts comprising metals or metal oxides or hydroxides, not provided for in group B01J21/00
- B01J23/70—Catalysts comprising metals or metal oxides or hydroxides, not provided for in group B01J21/00 of the iron group metals or copper
- B01J23/76—Catalysts comprising metals or metal oxides or hydroxides, not provided for in group B01J21/00 of the iron group metals or copper combined with metals, oxides or hydroxides provided for in groups B01J23/02 - B01J23/36
- B01J23/80—Catalysts comprising metals or metal oxides or hydroxides, not provided for in group B01J21/00 of the iron group metals or copper combined with metals, oxides or hydroxides provided for in groups B01J23/02 - B01J23/36 with zinc, cadmium or mercury
-
- B—PERFORMING OPERATIONS; TRANSPORTING
- B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
- B01J—CHEMICAL OR PHYSICAL PROCESSES, e.g. CATALYSIS OR COLLOID CHEMISTRY; THEIR RELEVANT APPARATUS
- B01J37/00—Processes, in general, for preparing catalysts; Processes, in general, for activation of catalysts
- B01J37/0009—Use of binding agents; Moulding; Pressing; Powdering; Granulating; Addition of materials ameliorating the mechanical properties of the product catalyst
- B01J37/0027—Powdering
- B01J37/0036—Grinding
-
- C—CHEMISTRY; METALLURGY
- C01—INORGANIC CHEMISTRY
- C01B—NON-METALLIC ELEMENTS; COMPOUNDS THEREOF; METALLOIDS OR COMPOUNDS THEREOF NOT COVERED BY SUBCLASS C01C
- C01B2203/00—Integrated processes for the production of hydrogen or synthesis gas
- C01B2203/02—Processes for making hydrogen or synthesis gas
- C01B2203/0266—Processes for making hydrogen or synthesis gas containing a decomposition step
- C01B2203/0277—Processes for making hydrogen or synthesis gas containing a decomposition step containing a catalytic decomposition step
-
- C—CHEMISTRY; METALLURGY
- C01—INORGANIC CHEMISTRY
- C01B—NON-METALLIC ELEMENTS; COMPOUNDS THEREOF; METALLOIDS OR COMPOUNDS THEREOF NOT COVERED BY SUBCLASS C01C
- C01B2203/00—Integrated processes for the production of hydrogen or synthesis gas
- C01B2203/10—Catalysts for performing the hydrogen forming reactions
- C01B2203/1041—Composition of the catalyst
- C01B2203/1076—Copper or zinc-based catalysts
-
- C—CHEMISTRY; METALLURGY
- C01—INORGANIC CHEMISTRY
- C01B—NON-METALLIC ELEMENTS; COMPOUNDS THEREOF; METALLOIDS OR COMPOUNDS THEREOF NOT COVERED BY SUBCLASS C01C
- C01B2203/00—Integrated processes for the production of hydrogen or synthesis gas
- C01B2203/10—Catalysts for performing the hydrogen forming reactions
- C01B2203/1041—Composition of the catalyst
- C01B2203/1082—Composition of support materials
-
- C—CHEMISTRY; METALLURGY
- C01—INORGANIC CHEMISTRY
- C01B—NON-METALLIC ELEMENTS; COMPOUNDS THEREOF; METALLOIDS OR COMPOUNDS THEREOF NOT COVERED BY SUBCLASS C01C
- C01B2203/00—Integrated processes for the production of hydrogen or synthesis gas
- C01B2203/12—Feeding the process for making hydrogen or synthesis gas
- C01B2203/1205—Composition of the feed
- C01B2203/1211—Organic compounds or organic mixtures used in the process for making hydrogen or synthesis gas
- C01B2203/1217—Alcohols
- C01B2203/1223—Methanol
Definitions
- the present invention relates to a catalyst for efficiently decomposing methanol to produce hydrogen and an apparatus comprising such a methanol-decomposing catalyst.
- Electric vehicles free from the problems of burning fuels generally run with excellent energy efficiency without emission of exhaust gas polluting the environment.
- the electric vehicles running by batteries are disadvantageous in many respects such as limited distance covered by one charge and a long charging time of batteries, which should be solved for cars running streets.
- the electric vehicles running with fuel cells utilizing an electrochemical reaction between hydrogen and oxygen have attracted much attention as alternatives to the prevalent engine vehicles.
- the electric vehicles with fuel cells are advantageous in energy efficiency free from the problems of exhaust gas.
- a hydrogen gas should be carried and supplied safely and efficiently in the fuel cells.
- methane or methanol is used as a hydrogen gas source to be decomposed to generate a hydrogen gas while running.
- methanol is most promising as a hydrogen gas source, because methanol is in a state of liquid that can easily be stored in a tank and supplied like gasoline.
- the methanol decomposition gas should have as high a hydrogen concentration as possible with minimum concentrations of by-products and unreacted methanol.
- the amount of a hydrogen gas required changes depending on whether or not and how automobiles are accelerated, leading to change in the amount of a fuel to be decomposed such as methanol and thus the temperature of the catalyst in a range of 200 to 600° C. Accordingly, the methanol-decomposing catalyst should have activity that little lowers for a long period of use in such a temperature range, and high thermal stability. Further, the methanol-decomposing catalyst should be maintenance-free because it is used on vehicles.
- methanol-decomposing catalysts are (a) catalysts produced by compressing catalytically active components such as oxides of copper, zinc, etc. into pellets with binders such as graphite; and (b) catalysts comprising noble metals such as palladium as catalytically active components.
- the catalysts (a) palletized with graphite do not have sufficiently large contact area with methanol, failing to achieve efficient decomposition of methanol in a small catalyst amount.
- the catalysts (b) comprising noble metals such as palladium as catalytically active components are poor in selectivity for generating hydrogen.
- Both catalysts suffer from the problem that the resultant gas does not contain a sufficiently high concentration of a hydrogen gas while containing relatively large amounts of by-products such as CO, etc. Thus, it is difficult to make smaller a methanol-decomposing apparatus for generating a hydrogen gas that is to be supplied to a fuel cell.
- an object of the present invention is to provide a methanol-decomposing catalyst having excellent durability at widely changeable temperatures for efficiently producing a reaction gas having a high hydrogen gas concentration with sufficiently suppressed by-products, and a methanol-decomposing apparatus comprising such a catalyst.
- a methanol-decomposing catalyst comprising catalytically active components comprising copper and zinc, and a carrier for supporting the catalytically active components and composed of zirconia and/or titania together with ceria can efficiently decompose methanol to produce a hydrogen gas while sufficiently suppressing undesired side-reactions.
- the present invention has been completed based upon this finding.
- the methanol-decomposing catalyst according to the present invention comprises catalytically active components of copper and zinc supported by a carrier composed of zirconia and/or titania together with ceria. Ceria added to the carrier acts to suppress the side reactions, contributing to efficient production of a hydrogen gas.
- the ceria content is preferably 5 weight % or more based on the carrier to sufficiently suppress the side reactions.
- Copper and zinc are preferably present in the form of oxide on the carrier.
- a weight ratio of copper/zinc is preferably 1/10 to 10/1 on an oxide basis.
- the methanol-decomposing apparatus comprises the above methanol-decomposing catalyst and a means made of ceramics or metals for supporting the catalyst.
- FIG. 1 is a partially cross-sectional, side view showing an apparatus for methanol-decomposing experiment
- FIG. 2 is a graph showing the relation between the ceria content and the conversion ratio R of methanol in the methanol decomposition gas produced in the presence of the methanol-decomposing catalysts comprising a ceria/zirconia carrier and the methanol-decomposing catalysts of COMPERATIVE EXAMPLES, respectively;
- FIG. 3 is a graph showing the relation between the ceria content and the conversion ratio R of methanol in the methanol decomposition gas produced in the presence of the methanol-decomposing catalysts comprising a ceria/titania carrier and the methanol-decomposing catalysts of COMPERATIVE EXAMPLES, respectively;
- FIG. 4 is a graph showing the relation between the ceria content and the hydrogen concentration in the methanol decomposition gas produced in the presence of the methanol-decomposing catalysts comprising a ceria/zirconia carrier and the methanol-decomposing catalysts of COMPERATIVE EXAMPLES, respectively;
- FIG. 5 is a graph showing the relation between the ceria content and the hydrogen concentration in the methanol decomposition gas produced in the presence of the methanol-decomposing catalysts comprising a ceria/titania carrier and the methanol-decomposing catalysts of COMPERATIVE EXAMPLES, respectively;
- FIG. 6 is a graph showing the relation between the ceria content and the ether concentration in the methanol decomposition gas produced in the presence of the methanol-decomposing catalysts comprising a ceria/zirconia carrier and the methanol-decomposing catalysts of COMPERATIVE EXAMPLES, respectively; and
- FIG. 7 is a graph showing the relation between the ceria content and the ether concentration in the methanol decomposition gas produced in the presence of the methanol-decomposing catalysts comprising a ceria/titania carrier and the methanol-decomposing catalysts of COMPERATIVE EXAMPLES, respectively.
- the methanol-decomposing catalyst of the present invention comprises catalytically active components comprising copper and zinc and a carrier composed of zirconia and/or titania together with ceria for supporting the catalytically active components.
- the catalytically active components in the methanol-decomposing catalyst of the present invention comprise copper and zinc. These metals are usually present in the form of oxide on the carrier.
- a weight ratio of copper/zinc is preferably 1/10 to 10/1, more preferably 1/2 to 2/1 on an oxide basis.
- the carrier in the methanol-decomposing catalyst of the present invention is composed of zirconia and/or titania together with ceria.
- Zirconia and titania are preferably in the form of fine powder having an average diameter of 1 to 50 ⁇ m, more preferably 5 to 10 ⁇ m.
- the ceria content is preferably 5 weight % or more based on 100 weight % of the entire carrier to sufficiently suppress the side reactions.
- the ceria content is preferably 5 to 80 weight %, more preferably 10 to 60 weight %.
- the ceria content is 20 to 40 weight % while the zirconia content is 80 to 60 weight %.
- the ceria content is 30 to 50 weight % while the titania content is 70 to 50 weight %.
- Water-soluble salts such as nitrates, sulfates, chlorides, etc. of copper and zinc are dissolved in water to provide an aqueous solution.
- Water-soluble salts of other metals (aluminum, etc.) than copper and zinc may also be added to the aqueous solution, if necessary.
- Alkaline salts such as NaOH, NaHCO 3 , Na 2 CO 3 , etc. are added to the aqueous solution to coprecipitate the catalyst precursors of copper and zinc in the form of hydroxide, carbonate, etc., which are then filtered out.
- the resultant catalyst precursor powder of copper and zinc is mixed with zirconia and/or titania powder and ceria powder in a suitable amount of water in a ball mill, etc. to form a uniform slurry.
- the formed body is preferably baked at about 300 to 600° C., so that the catalyst precursors are converted to copper oxide and zinc oxide.
- the support may preferably be made of ceramics or metals, and it is preferably in the form of honeycomb from the aspect of gas penetration resistance.
- the methanol-decomposing catalyst carried by a support such as a honeycomb support is disposed in a suitable casing.
- a methanol-decomposing apparatus is constituted by equipping the casing with a reactant-supplying pipe, a reaction gas-discharging pipe and a means for heating the support.
- the carrier supporting the catalytically active components may be compression-molded to pellets, which are filled in a suitable casing.
- Methanol is introduced into the methanol-decomposing apparatus together with air and water through the reactant-supplying pipe to cause a methanol-decomposing reaction therein.
- the temperature of the catalyst changes in a range of about 200 to 600° C. depending on acceleration and deceleration of the automobiles, and the methanol-decomposing catalyst of the present invention exhibits sufficiently high catalytic activity in this temperature range. Because the temperature of the catalyst is not sufficiently high at start of automobiles, the methanol-decomposing catalyst should be heated by the heater mounted to the methanol-decomposing apparatus. Combustion heat of methanol may preferably be utilized as a heat source.
- Zirconia powder (purity: 98% or more, average particle diameter: 5 ⁇ m) or titania powder (purity: 98% or more, average particle diameter: 4 ⁇ m) was mixed with ceria powder (purity: 98% or more, average particle diameter: 4 ⁇ m) at weight ratios shown in Table 1 to produce carrier powder mixtures.
- ceria powder purity: 98% or more, average particle diameter: 4 ⁇ m
- Table 1 weight ratios shown in Table 1 to produce carrier powder mixtures.
- Added to 90 g of each carrier powder mixture was 10 g of the above precursors consisting of copper carbonate and zinc carbonate, and the resultant mixture was ball-milled in a suitable amount of water to provide a uniform slurry. The slurry was filtered to obtain solid components, which were washed with water, dried, baked at 400° C.
- Example No. 1-2 The resultant catalyst was measured with respect to the amounts of copper and zinc (on a metal basis) in the catalytically active components by emission spectroscopic analysis. The measurement results are shown in Table 1.
- EXAMPLE 1 was repeated except for using only zirconia instead of zirconia+ceria as a carrier to produce a methanol-decomposing catalyst (Sample No. 1-1).
- the resultant catalyst was measured with respect to the amounts of copper and zinc (on a metal basis) in the same manner as in EXAMPLE 1.
- the formulations of the catalyst are shown in Table 1.
- EXAMPLE 1 was repeated except for using only titania instead of zirconia+ceria as a carrier to produce a methanol-decomposing catalyst (Sample No. 2-1).
- the resultant catalyst was measured with respect to the amounts of copper and zinc (on a metal basis) in the same manner as in EXAMPLE 1.
- the formulations of the catalyst are shown in Table 1.
- EXAMPLE 1 was repeated except for using only ceria instead of zirconia+ceria as a carrier to produce a methanol-decomposing catalyst (Sample No. 3).
- the resultant catalyst was measured with respect to the amounts of copper and zinc (on a metal basis) in the same manner as in EXAMPLE 1.
- the formulations of the catalyst are shown in Table 1.
- EXAMPLE 1 was repeated except for using alumina having an average particle diameter of 8 ⁇ m instead of zirconia+ceria as a carrier to produce a methanol-decomposing catalyst (Sample No. 4).
- the resultant catalyst was measured with respect to the amounts of copper and zinc (on a metal basis) in the same manner as in EXAMPLE 1.
- the formulations of the catalyst are shown in Table 1.
- the apparatus has a glass tube 1 having an inner diameter of 9 mm, which is filled with a pair of glass-wool layers 2 a, 2 b and a methanol-decomposing catalyst layer 3 of 11.8 mm in height sandwiched by the glass-wool layers 2 a, 2 b and seals 4 a, 4 b plugging the openings 1 a, 1 b of the glass tube 1 .
- a reactant-supplying pipe 10 and a thermo-couple 12 are inserted into the glass tube 1 through the upper seal 4 a.
- the reactant-supplying pipe 10 is connected to an evaporator 6 to which methanol and water are supplied, and an air-introducing pipe 8 .
- a reaction product-discharging pipe 14 is inserted into the glass tube 1 through the lower seal 4 b and connected to a gas chromatograph 20 .
- a heating wire 16 connected to a power source 18 is wound around the glass tube 1 .
- the methanol-decomposing reaction was performed by introducing a mixture of a methanol vapor, air and steam at 200° C. into the glass tube 1 through the pipe 10 , while controlling the temperature of the catalyst by the heating wire 16 at such a level that the temperature of the glass tube 1 at an exit was kept at 300° C.
- the reaction conditions were as follows:
- Amount of the catalyst 0.75 ml
- Methanol-supplying rate 7.5 ml/hour.
- the reaction product gas was analyzed by the gas chromatograph 20 to determine a methanol conversion ratio R (%), and the concentrations (%) of hydrogen and ether in the reaction product gas.
- the methanol conversion ratio R was calculated by the following equation:
- [CH 3 OH], [CO 2 ] and [CO] represent the concentrations of unreacted methanol, carbon dioxide and carbon monoxide, respectively, in the reaction product.
- the methanol-decomposing catalyst of the present invention comprising catalytically active components containing copper and zinc and a carrier composed of zirconia and/or titania together with ceria is much more efficient in the decomposition of methanol to hydrogen while suppressing side reactions than the conventional methanol-decomposing catalysts. Because the methanol-decomposing catalyst of the present invention can efficiently decompose methanol in a small catalyst amount, a methanol-decomposing apparatus can be made small with high catalytic activity. Further, when the methanol-decomposing catalyst of the present invention is used in a temperature range of about 200 to 600° C. to which the catalyst may reach on automobiles for a long period of time, it exhibits a high thermal stability without much losing its catalytic activity. In addition, the methanol-decomposing catalyst of the present invention can be used maintenance-free.
Landscapes
- Chemical & Material Sciences (AREA)
- Organic Chemistry (AREA)
- Engineering & Computer Science (AREA)
- Chemical Kinetics & Catalysis (AREA)
- Materials Engineering (AREA)
- Health & Medical Sciences (AREA)
- General Health & Medical Sciences (AREA)
- Combustion & Propulsion (AREA)
- Inorganic Chemistry (AREA)
- Catalysts (AREA)
- Hydrogen, Water And Hydrids (AREA)
Abstract
A methanol-decomposing catalyst comprises catalytically active components containing copper and zinc, and a carrier composed of zirconia and/or titania and ceria for supporting the catalytically active components. The methanol-decomposing catalyst has excellent catalytic activity, thereby efficiently producing a hydrogen gas while suppressing side reactions.
Description
- The present invention relates to a catalyst for efficiently decomposing methanol to produce hydrogen and an apparatus comprising such a methanol-decomposing catalyst.
- Though most of energy sources for automobiles have conventionally been petroleum fuels such as gasoline, diesel oil, etc., alternative energy sources have been attracting much attention in view of the depletion of petroleum oil and various environmental problems such as warming of global climate, acid rain, etc. Such alternative energy sources are non-petroleum engine fuels such as a natural gas and methanol, and batteries and fuel cells for electric vehicles, and some of them have already been practically used.
- Engines running with non-petroleum fuels such as a natural gas and methanol are advantageous in less emission of CO2 and noxious gases such as NOx than the gasoline or diesel engines. However, the non-petroleum fuels are still derived from limited sources of fossil fuels.
- Electric vehicles free from the problems of burning fuels generally run with excellent energy efficiency without emission of exhaust gas polluting the environment. However, the electric vehicles running by batteries are disadvantageous in many respects such as limited distance covered by one charge and a long charging time of batteries, which should be solved for cars running streets.
- In view of such circumstances, the electric vehicles running with fuel cells utilizing an electrochemical reaction between hydrogen and oxygen have attracted much attention as alternatives to the prevalent engine vehicles. The electric vehicles with fuel cells are advantageous in energy efficiency free from the problems of exhaust gas. However, a hydrogen gas should be carried and supplied safely and efficiently in the fuel cells. It is thus recently proposed that methane or methanol is used as a hydrogen gas source to be decomposed to generate a hydrogen gas while running. In particular, methanol is most promising as a hydrogen gas source, because methanol is in a state of liquid that can easily be stored in a tank and supplied like gasoline.
- When methanol is decomposed to produce a hydrogen gas, the following reactions:
- CH3OH→HCHO+H2, and
- HCHO+H2O→CO2+2H2
- mainly occur with inevitable side reactions generating by-products such as carbon monoxide. Because a gas produced by methanol decomposition is directly introduced into a fuel cell, the methanol decomposition gas should have as high a hydrogen concentration as possible with minimum concentrations of by-products and unreacted methanol.
- The amount of a hydrogen gas required changes depending on whether or not and how automobiles are accelerated, leading to change in the amount of a fuel to be decomposed such as methanol and thus the temperature of the catalyst in a range of 200 to 600° C. Accordingly, the methanol-decomposing catalyst should have activity that little lowers for a long period of use in such a temperature range, and high thermal stability. Further, the methanol-decomposing catalyst should be maintenance-free because it is used on vehicles.
- Conventionally known as such methanol-decomposing catalysts are (a) catalysts produced by compressing catalytically active components such as oxides of copper, zinc, etc. into pellets with binders such as graphite; and (b) catalysts comprising noble metals such as palladium as catalytically active components. However, the catalysts (a) palletized with graphite do not have sufficiently large contact area with methanol, failing to achieve efficient decomposition of methanol in a small catalyst amount. The catalysts (b) comprising noble metals such as palladium as catalytically active components are poor in selectivity for generating hydrogen.
- Both catalysts suffer from the problem that the resultant gas does not contain a sufficiently high concentration of a hydrogen gas while containing relatively large amounts of by-products such as CO, etc. Thus, it is difficult to make smaller a methanol-decomposing apparatus for generating a hydrogen gas that is to be supplied to a fuel cell.
- Accordingly, an object of the present invention is to provide a methanol-decomposing catalyst having excellent durability at widely changeable temperatures for efficiently producing a reaction gas having a high hydrogen gas concentration with sufficiently suppressed by-products, and a methanol-decomposing apparatus comprising such a catalyst.
- As a result of intense research in view of the above object, the inventors have found that a methanol-decomposing catalyst comprising catalytically active components comprising copper and zinc, and a carrier for supporting the catalytically active components and composed of zirconia and/or titania together with ceria can efficiently decompose methanol to produce a hydrogen gas while sufficiently suppressing undesired side-reactions. The present invention has been completed based upon this finding.
- The methanol-decomposing catalyst according to the present invention comprises catalytically active components of copper and zinc supported by a carrier composed of zirconia and/or titania together with ceria. Ceria added to the carrier acts to suppress the side reactions, contributing to efficient production of a hydrogen gas.
- The ceria content is preferably 5 weight % or more based on the carrier to sufficiently suppress the side reactions. Copper and zinc are preferably present in the form of oxide on the carrier. To achieve high efficiency in the production of a hydrogen gas, a weight ratio of copper/zinc is preferably 1/10 to 10/1 on an oxide basis.
- The methanol-decomposing apparatus according to the present invention comprises the above methanol-decomposing catalyst and a means made of ceramics or metals for supporting the catalyst.
- FIG. 1 is a partially cross-sectional, side view showing an apparatus for methanol-decomposing experiment;
- FIG. 2 is a graph showing the relation between the ceria content and the conversion ratio R of methanol in the methanol decomposition gas produced in the presence of the methanol-decomposing catalysts comprising a ceria/zirconia carrier and the methanol-decomposing catalysts of COMPERATIVE EXAMPLES, respectively;
- FIG. 3 is a graph showing the relation between the ceria content and the conversion ratio R of methanol in the methanol decomposition gas produced in the presence of the methanol-decomposing catalysts comprising a ceria/titania carrier and the methanol-decomposing catalysts of COMPERATIVE EXAMPLES, respectively;
- FIG. 4 is a graph showing the relation between the ceria content and the hydrogen concentration in the methanol decomposition gas produced in the presence of the methanol-decomposing catalysts comprising a ceria/zirconia carrier and the methanol-decomposing catalysts of COMPERATIVE EXAMPLES, respectively;
- FIG. 5 is a graph showing the relation between the ceria content and the hydrogen concentration in the methanol decomposition gas produced in the presence of the methanol-decomposing catalysts comprising a ceria/titania carrier and the methanol-decomposing catalysts of COMPERATIVE EXAMPLES, respectively;
- FIG. 6 is a graph showing the relation between the ceria content and the ether concentration in the methanol decomposition gas produced in the presence of the methanol-decomposing catalysts comprising a ceria/zirconia carrier and the methanol-decomposing catalysts of COMPERATIVE EXAMPLES, respectively; and
- FIG. 7 is a graph showing the relation between the ceria content and the ether concentration in the methanol decomposition gas produced in the presence of the methanol-decomposing catalysts comprising a ceria/titania carrier and the methanol-decomposing catalysts of COMPERATIVE EXAMPLES, respectively.
- [1] Methanol-Decomposing Catalyst
- The methanol-decomposing catalyst of the present invention comprises catalytically active components comprising copper and zinc and a carrier composed of zirconia and/or titania together with ceria for supporting the catalytically active components.
- (2) Catalytically Active Components
- The catalytically active components in the methanol-decomposing catalyst of the present invention comprise copper and zinc. These metals are usually present in the form of oxide on the carrier. A weight ratio of copper/zinc is preferably 1/10 to 10/1, more preferably 1/2 to 2/1 on an oxide basis.
- (2) Carrier
- The carrier in the methanol-decomposing catalyst of the present invention is composed of zirconia and/or titania together with ceria. Zirconia and titania are preferably in the form of fine powder having an average diameter of 1 to 50 μm, more preferably 5 to 10 μm.
- The ceria content is preferably 5 weight % or more based on 100 weight % of the entire carrier to sufficiently suppress the side reactions. When the ceria content exceeds 80 weight %, the catalytic activity slightly lowers. Therefore, the ceria content is preferably 5 to 80 weight %, more preferably 10 to 60 weight %. In the case of ceria + zirconia, it is preferable that the ceria content is 20 to 40 weight % while the zirconia content is 80 to 60 weight %. Also, in the case of ceria + titania, it is preferable that the ceria content is 30 to 50 weight % while the titania content is 70 to 50 weight %.
- The use of such a carrier provides the methanol-decomposing catalyst with high activity and excellent selectivity. The reasons therefor are not necessarily clear, but it may be considered that copper oxide and zinc oxide as the catalytically active components are finely dispersed in a carrier composed of zirconia and/or titania together with ceria, exhibiting good interaction therebetween.
- [2] Production of Methanol-Decomposing Catalyst
- (1) Starting Materials for Catalyst
- To have a carrier support copper and zinc in the form of oxide, it is preferable to prepare an aqueous solution containing compounds of copper and zinc, from which catalyst precursors of copper and zinc are precipitated in the form of fine powder.
- Water-soluble salts such as nitrates, sulfates, chlorides, etc. of copper and zinc are dissolved in water to provide an aqueous solution. Water-soluble salts of other metals (aluminum, etc.) than copper and zinc may also be added to the aqueous solution, if necessary. Alkaline salts such as NaOH, NaHCO3, Na2CO3, etc. are added to the aqueous solution to coprecipitate the catalyst precursors of copper and zinc in the form of hydroxide, carbonate, etc., which are then filtered out.
- (2) Supporting Catalytically Active Components
- The resultant catalyst precursor powder of copper and zinc is mixed with zirconia and/or titania powder and ceria powder in a suitable amount of water in a ball mill, etc. to form a uniform slurry. After formed into pellets or applied to a proper support, the formed body is preferably baked at about 300 to 600° C., so that the catalyst precursors are converted to copper oxide and zinc oxide. The support may preferably be made of ceramics or metals, and it is preferably in the form of honeycomb from the aspect of gas penetration resistance.
- [3] Methanol-Decomposing Apparatus
- The methanol-decomposing catalyst carried by a support such as a honeycomb support is disposed in a suitable casing. A methanol-decomposing apparatus is constituted by equipping the casing with a reactant-supplying pipe, a reaction gas-discharging pipe and a means for heating the support. Instead of carrying the methanol-decomposing catalyst by a support, the carrier supporting the catalytically active components may be compression-molded to pellets, which are filled in a suitable casing.
- [4] Methanol-Decomposing Method
- Methanol is introduced into the methanol-decomposing apparatus together with air and water through the reactant-supplying pipe to cause a methanol-decomposing reaction therein. The temperature of the catalyst changes in a range of about 200 to 600° C. depending on acceleration and deceleration of the automobiles, and the methanol-decomposing catalyst of the present invention exhibits sufficiently high catalytic activity in this temperature range. Because the temperature of the catalyst is not sufficiently high at start of automobiles, the methanol-decomposing catalyst should be heated by the heater mounted to the methanol-decomposing apparatus. Combustion heat of methanol may preferably be utilized as a heat source.
- The present invention will be explained in further detail by the following examples without intention of restricting the scope of the present invention defined by the claims attached hereto.
- 12.2 g of copper nitrate and 16.8 g of zinc nitrate were dissolved in 0.8 L of water. Introduced into the aqueous solution while stirring at 50° C. was an aqueous solution of sodium hydrogen carbonate in an amount of two times the stoichiometric amount, so that copper carbonate and zinc carbonate were precipitated in the solution. The solution was filtered to obtain solid components, which were then washed with water and dried to provide a mixture of copper carbonate and zinc carbonate as the precursors of the catalytically active components.
- Zirconia powder (purity: 98% or more, average particle diameter: 5 μm) or titania powder (purity: 98% or more, average particle diameter: 4 μm) was mixed with ceria powder (purity: 98% or more, average particle diameter: 4 μm) at weight ratios shown in Table 1 to produce carrier powder mixtures. Added to 90 g of each carrier powder mixture was 10 g of the above precursors consisting of copper carbonate and zinc carbonate, and the resultant mixture was ball-milled in a suitable amount of water to provide a uniform slurry. The slurry was filtered to obtain solid components, which were washed with water, dried, baked at 400° C. for 2 hours in the air, pulverized, and then classified to obtain methanol-decomposing catalyst particles having an average diameter of 0.5 to 1 mm (Sample No. 1-2). The resultant catalyst was measured with respect to the amounts of copper and zinc (on a metal basis) in the catalytically active components by emission spectroscopic analysis. The measurement results are shown in Table 1.
- These processes were repeated with various formulations of carriers (zirconia or titania plus ceria) and catalytically active components (copper and zinc), to produce methanol-decomposing catalysts of Sample Nos. 1-3 to 1-7 and 2-2 to 2-7. These formulations are shown in Table 1.
- EXAMPLE 1 was repeated except for using only zirconia instead of zirconia+ceria as a carrier to produce a methanol-decomposing catalyst (Sample No. 1-1). The resultant catalyst was measured with respect to the amounts of copper and zinc (on a metal basis) in the same manner as in EXAMPLE 1. The formulations of the catalyst are shown in Table 1.
- EXAMPLE 1 was repeated except for using only titania instead of zirconia+ceria as a carrier to produce a methanol-decomposing catalyst (Sample No. 2-1). The resultant catalyst was measured with respect to the amounts of copper and zinc (on a metal basis) in the same manner as in EXAMPLE 1. The formulations of the catalyst are shown in Table 1.
- EXAMPLE 1 was repeated except for using only ceria instead of zirconia+ceria as a carrier to produce a methanol-decomposing catalyst (Sample No. 3). The resultant catalyst was measured with respect to the amounts of copper and zinc (on a metal basis) in the same manner as in EXAMPLE 1. The formulations of the catalyst are shown in Table 1.
- EXAMPLE 1 was repeated except for using alumina having an average particle diameter of 8 μm instead of zirconia+ceria as a carrier to produce a methanol-decomposing catalyst (Sample No. 4). The resultant catalyst was measured with respect to the amounts of copper and zinc (on a metal basis) in the same manner as in EXAMPLE 1. The formulations of the catalyst are shown in Table 1.
- Added to catalytically active components containing copper and zinc was graphite as a binder in an amount of 30 weight % based on the catalyst. The resultant mixture was compression-molded into a disc-shaped methanol-decomposing catalyst with no carrier having a diameter of 15 mm and a thickness of 2 mm (Sample No. 5). The resultant catalyst was measured with respect to the amounts of copper and zinc (on a metal basis) in the same manner as in EXAMPLE 1. The formulations of the catalyst are shown in Table 1.
TABLE 1 Formulations of Methanol-Decomposing Catalysts Catalytically Active Sample Carrier(1) Components(2) No. CeO2 ZrO2 TiO2 Al2O3 Cu Zn 1-1(3) — 100 — — 2.6 2.4 1-2 5 95 — — 2.5 2.5 1-3 10 90 — — 2.5 2.6 1-4 20 80 — — 2.5 2.7 1-5 40 60 — — 2.3 2.5 1-6 60 40 — — 2.5 2.6 1-7 80 20 — — 2.5 2.6 2-1(4) — — 100 — 2.5 2.7 2-2 5 — 95 — 2.6 2.4 2-3 10 — 90 — 2.5 2.6 2-4 20 — 80 — 2.5 2.7 2-5 40 — 60 — 2.4 2.6 2-6 60 — 40 — 2.5 2.6 2-7 80 — 20 — 2.3 2.5 3(5) 100 — — — 2.5 2.3 4(6) — — — 100 2.6 2.6 5(7) — — — — 32.0 36.0 - The methanol-decomposing catalysts produced in EXAMPLE 1 (Sample Nos. 1-2 to 1-7 and 2-2 to 2-7 )and COMPERATIVE EXAMPLES 1-5 (Sample Nos. 1-1, 2-1, and 3 to 5) were subjected to methanol decomposition experiments. An apparatus for the methanol decomposition experiments is shown in FIG. 1.
- In FIG. 1, the apparatus has a glass tube1 having an inner diameter of 9 mm, which is filled with a pair of glass-
wool layers catalyst layer 3 of 11.8 mm in height sandwiched by the glass-wool layers openings 1 a, 1 b of the glass tube 1. A reactant-supplyingpipe 10 and a thermo-couple 12 are inserted into the glass tube 1 through theupper seal 4 a. The reactant-supplyingpipe 10 is connected to anevaporator 6 to which methanol and water are supplied, and an air-introducingpipe 8. A reaction product-dischargingpipe 14 is inserted into the glass tube 1 through thelower seal 4 b and connected to agas chromatograph 20. Aheating wire 16 connected to apower source 18 is wound around the glass tube 1. - The methanol-decomposing reaction was performed by introducing a mixture of a methanol vapor, air and steam at 200° C. into the glass tube1 through the
pipe 10, while controlling the temperature of the catalyst by theheating wire 16 at such a level that the temperature of the glass tube 1 at an exit was kept at 300° C. The reaction conditions were as follows: - Reaction temperature: 300° C.,
- Amount of the catalyst: 0.75 ml,
- LHSV=10*,
- Steam/methanol (mole ratio)=2.0,
- Air/methanol (mole ratio)=0.72, and
- Methanol-supplying rate: 7.5 ml/hour.
- Note: “LHSV=10” means that the amount of methanol decomposed in an hour was ten times that of the catalyst.
- The reaction product gas was analyzed by the
gas chromatograph 20 to determine a methanol conversion ratio R (%), and the concentrations (%) of hydrogen and ether in the reaction product gas. The methanol conversion ratio R was calculated by the following equation: - R/100(%)=1−[CH3OH]/{[CO2]+[CO]+[CH3OH]},
- wherein, [CH3OH], [CO2] and [CO] represent the concentrations of unreacted methanol, carbon dioxide and carbon monoxide, respectively, in the reaction product.
- The conversion ratio R of methanol, and the concentrations of hydrogen and ether in the resultant methanol decomposition gas are plotted against the ceria content in the case of using the catalysts of Sample Nos. 1-1 to 1-7 and 3 each comprising a ceria and/or zirconia carrier in FIGS. 2, 4 and6, and in the case of using the catalysts of Sample Nos. 2-1 to 2-7 and 3 each comprising a ceria and/or titania carrier in FIGS. 3, 5 and 7.
- Referring to FIGS. 2 and 4, the comparison of the catalysts of Sample Nos. 1-2 to 1-7 each comprising a ceria/zirconia carrier containing 5 weight % or more of ceria with the catalyst of Sample No. 1-1 containing no ceria revealed that the former were remarkably improved than the latter in a methanol conversion ratio R (Sample Nos. 1-2 to 1-7: 87 to 100%, Sample No. 1-1: 67%) and a hydrogen concentration (Sample Nos. 1-2 to -1-7: about 40%, Sample No. 1-1: 27%). Also, the methanol-decomposing catalyst of Sample No. 3 comprising a ceria carrier exhibited a slightly lower hydrogen concentration than those of the catalysts of Sample Nos. 1-2 to 1-7. Thus, it is confirmed that the ceria content in the ceria/zirconia carrier for the methanol-decomposing catalyst is preferably 5 to 80 weight %, more preferably 20 to 40 weight %.
- Referring to FIGS. 3 and 5, the comparison of the catalysts of Sample Nos. 2-2 to 2-7 each comprising a ceria/titania carrier containing 5 weight % or more of ceria with the catalyst of Sample No. 2-1 containing only titania without ceria revealed that the former were remarkably improved than the latter in a methanol conversion ratio R (Sample Nos. 2-2 to-2-7: 82 to 100%, Sample No. 2-1: 60%) and a hydrogen concentration (Sample Nos. 2-2 to 2-7: 34 to 41%, Sample No. 2-1: 26%). Thus, it is confirmed that the ceria content in the ceria/titania carrier for the methanol-decomposing catalyst is preferably 5 to 80 weight %, more preferably 30 to 50 weight %.
- In the case of the catalyst of Sample No. 4 (COMPEATIVE EXAMPLE 4) comprising an alumina carrier, the hydrogen concentration in the methanol decomposition product was slightly low, though the methanol conversion ratio R was high. In addition, ethers (mainly dimethyl ether) were produced with this catalyst (see FIGS. 6 and 7), meaning that the selectivity of the hydrogen-producing reaction is low in the case of using a catalyst comprising an alumina carrier. This suggests that side reactions take place to an unneglectful extent in addition to the methanol decomposition reaction on the alumina carrier, implying that alumina is not preferable as a carrier for the methanol-decomposing catalyst.
- Further, the comparison of the methanol-decomposing catalysts of EXAMPLE 1 with that of COMPARATIVE EXAMPLE 5 (Sample No. 5) revealed that the amounts of the catalytically active components necessary in the former catalysts were as small as about 18% of those of the latter catalyst. It is thus concluded that the addition of ceria to the carrier of zirconia and/or titania serves to drastically reduce the amounts of the catalytically active components in the methanol-decomposing catalysts.
- As described above in detail, the methanol-decomposing catalyst of the present invention comprising catalytically active components containing copper and zinc and a carrier composed of zirconia and/or titania together with ceria is much more efficient in the decomposition of methanol to hydrogen while suppressing side reactions than the conventional methanol-decomposing catalysts. Because the methanol-decomposing catalyst of the present invention can efficiently decompose methanol in a small catalyst amount, a methanol-decomposing apparatus can be made small with high catalytic activity. Further, when the methanol-decomposing catalyst of the present invention is used in a temperature range of about 200 to 600° C. to which the catalyst may reach on automobiles for a long period of time, it exhibits a high thermal stability without much losing its catalytic activity. In addition, the methanol-decomposing catalyst of the present invention can be used maintenance-free.
Claims (9)
1. A methanol-decomposing catalyst comprising catalytically active components composed of copper and zinc, and a carrier for supporting said catalytically active components, said carrier being composed of zirconia and/or titania together with ceria.
2. The methanol-decomposing catalyst according to claim 1 , wherein the ceria content is 5 weight % or more based on said carrier.
3. The methanol-decomposing catalyst according to claim 1 , wherein copper and zinc are present in the form of oxide.
4. The methanol-decomposing catalyst according to claim 2 , wherein copper and zinc are present in the form of oxide.
5. The methanol-decomposing catalyst according to claim 1 , wherein a weight ratio of copper/zinc is 1/10 to 10/1 on an oxide basis in said catalytically active components.
6. The methanol-decomposing catalyst according to claim 2 , wherein a weight ratio of copper/zinc is 1/10 to 10/1 on an oxide basis in said catalytically active components.
7. The methanol-decomposing catalyst according to claim 3 , wherein a weight ratio of copper/zinc is 1/10 to 10/1 on an oxide basis in said catalytically active components.
8. The methanol-decomposing catalyst according to claim 4 , wherein a weight ratio of copper/zinc is 1/10 to 10/1 on an oxide basis in said catalytically active components.
9. A methanol-decomposing apparatus comprising a methanol-decomposing catalyst and a support made of ceramics or metals for supporting said catalyst, said catalyst comprising catalytically active components composed of copper and zinc, and a carrier for supporting said catalytically active components, said carrier being composed of zirconia and/or titania together with ceria.
Applications Claiming Priority (2)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
JP32860098A JP3624722B2 (en) | 1998-11-18 | 1998-11-18 | Methanol reforming catalyst and methanol reforming catalyst apparatus using the same |
JP10-328600 | 1998-11-18 |
Publications (2)
Publication Number | Publication Date |
---|---|
US20030148880A1 true US20030148880A1 (en) | 2003-08-07 |
US6649562B2 US6649562B2 (en) | 2003-11-18 |
Family
ID=18212095
Family Applications (1)
Application Number | Title | Priority Date | Filing Date |
---|---|---|---|
US09/442,761 Expired - Fee Related US6649562B2 (en) | 1998-11-18 | 1999-11-18 | Methanol-decomposing catalyst and methanol-decomposing apparatus comprising same |
Country Status (2)
Country | Link |
---|---|
US (1) | US6649562B2 (en) |
JP (1) | JP3624722B2 (en) |
Cited By (2)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
EP1243633A4 (en) * | 2000-10-02 | 2009-05-27 | Mitsui Mining & Smelting Co | Cerium based abrasive material and method for producing cerium based abrasive material |
US11059719B2 (en) | 2016-04-26 | 2021-07-13 | Haldor Topsøe A/S | Process for producing hydrogen or syngas by methanol cracking |
Families Citing this family (6)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
JP4724860B2 (en) * | 2005-10-19 | 2011-07-13 | 国立大学法人 大分大学 | Method for producing hydrogen production catalyst |
US7824654B2 (en) * | 2005-11-23 | 2010-11-02 | Wilson Mahlon S | Method and apparatus for generating hydrogen |
EP2221104B1 (en) * | 2007-12-14 | 2021-08-18 | Nissan Motor Co., Ltd. | Purification catalyst |
JP5498009B2 (en) * | 2008-10-30 | 2014-05-21 | 国立大学法人 東京大学 | Photocatalyst material, organic matter decomposition method, interior member, air cleaning device, oxidizer manufacturing device |
US8404908B2 (en) * | 2009-10-13 | 2013-03-26 | Uop Llc | Process for lignin conversion to chemicals or fuels with H2 generated from lignin depolymerization products |
US10130933B2 (en) * | 2016-12-29 | 2018-11-20 | King Abdulaziz University | Zn—CeO2—ZrO2 catalyst for hydrogen production via methanol partial oxidation |
Family Cites Families (11)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
JPS59199042A (en) | 1983-04-28 | 1984-11-12 | Nissan Motor Co Ltd | Catalyst for reforming methanol |
DE3340569A1 (en) | 1983-11-09 | 1985-05-23 | Sued Chemie Ag | CATALYST FOR THE PRODUCTION OF SYNTHESIS GAS OR FROM HYDROGEN AND METHOD FOR THE PRODUCTION THEREOF |
US4579995A (en) | 1984-06-29 | 1986-04-01 | Exxon Research And Engineering Co. | Process for the conversion of methanol to hydrocarbons |
US4946667A (en) | 1985-06-10 | 1990-08-07 | Engelhard Corporation | Method of steam reforming methanol to hydrogen |
FR2611194B1 (en) | 1987-02-19 | 1989-05-19 | Inst Francais Du Petrole | PROCESS FOR THE MANUFACTURE OF SYNTHESIS GAS OR HYDROGEN, BY CATALYTIC CONVERSION OF METHANOL TO LIQUID PHASE |
DE3736557A1 (en) | 1987-10-28 | 1989-05-11 | Sued Chemie Ag | CATALYST FOR THE SELECTIVE HYDROGENATION OF MULTIPLE UNSATURATED HYDROCARBONS |
JPH0635401B2 (en) | 1990-09-13 | 1994-05-11 | 工業技術院長 | Method for producing methanol from carbon dioxide |
DE69427932T2 (en) | 1993-05-10 | 2002-04-04 | Sakai Chemical Industry Co | Catalyst for the catalytic reduction of nitrogen oxides |
US5665668A (en) | 1994-01-25 | 1997-09-09 | Grigorova; Bojidara | Method of making a catalyst |
ATE179907T1 (en) | 1994-11-02 | 1999-05-15 | Anglo American Res Lab Pty Ltd | CATALYST WITH ZIRCONIA/CER OXIDE SUPPORT |
DE19739773A1 (en) | 1997-09-10 | 1999-03-11 | Basf Ag | Process and catalyst for steam reforming of methanol |
-
1998
- 1998-11-18 JP JP32860098A patent/JP3624722B2/en not_active Expired - Fee Related
-
1999
- 1999-11-18 US US09/442,761 patent/US6649562B2/en not_active Expired - Fee Related
Cited By (2)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
EP1243633A4 (en) * | 2000-10-02 | 2009-05-27 | Mitsui Mining & Smelting Co | Cerium based abrasive material and method for producing cerium based abrasive material |
US11059719B2 (en) | 2016-04-26 | 2021-07-13 | Haldor Topsøe A/S | Process for producing hydrogen or syngas by methanol cracking |
Also Published As
Publication number | Publication date |
---|---|
JP3624722B2 (en) | 2005-03-02 |
US6649562B2 (en) | 2003-11-18 |
JP2000153157A (en) | 2000-06-06 |
Similar Documents
Publication | Publication Date | Title |
---|---|---|
Luengnaruemitchai et al. | Selective catalytic oxidation of CO in the presence of H2 over gold catalyst | |
US6361757B1 (en) | Catalyst for manufacturing hydrogen or synthesis gas and manufacturing method of hydrogen or synthesis gas | |
Takeishi et al. | Steam reforming of dimethyl ether | |
CN101743343B (en) | Electrolysis of carbon dioxide in aqueous media to carbon monoxide and hydrogen for production of methanol | |
Ai et al. | Effect of surface and bulk palladium doping on the catalytic activity of La 2 Sn 2 O 7 pyrochlore oxides for diesel soot oxidation | |
US6649562B2 (en) | Methanol-decomposing catalyst and methanol-decomposing apparatus comprising same | |
EP3586959A1 (en) | Method for producing catalysts of formula my(ce1-xlxo2-x/2)1-y for the use thereof in the reverse water-gas shift reaction and partial oxidation of methane into synthesis gas by means of the method of combustion in solution | |
Patel et al. | Influence of preparation method on performance of Cu (Zn)(Zr)-alumina catalysts for the hydrogen production via steam reforming of methanol | |
JP2001522122A (en) | Gold catalyst for fuel cells | |
US6562499B1 (en) | Catalyst and method for selectively oxidizing carbon monoxide in hydrogen-containing gas and solid polymer electrolyte-type fuel cell system using such catalyst | |
Humphreys et al. | Advancements in Green Ammonia Production and Utilisation Technologies | |
JP3697591B2 (en) | Thin film photocatalytic chemical converter | |
CA1305847C (en) | Method of catalytically oxidizing alcohol vapor accompanied by varying amounts of excess oxygen | |
KR100711509B1 (en) | Hybrid metal catalyst supported on alumina for hydrogen production from the mixture of water and ethanol, production method thereof and the production method of hydrogen by auto-thermal reforming using said catalyst | |
JPS58193736A (en) | Catalyst for production of gas enriched with hydrogen | |
Welles et al. | A novel solid oxide fuel cell based catalytic converter replacement for enhanced emission control and power generation in automotive exhaust | |
JPS60202740A (en) | Catalyst for reforming methanol | |
JPS6241063B2 (en) | ||
JP4120862B2 (en) | Catalyst for CO shift reaction | |
CN111389436A (en) | Preparation method of efficient and stable molybdenum carbide catalyst for dimethyl ether steam reforming hydrogen production | |
JPS58193737A (en) | Catalyst for production of gas enriched with hydrogen | |
JPH0425064B2 (en) | ||
JPH0347894B2 (en) | ||
Golunski | Gas-phase catalysis by platinum-group metals—past, present, and future | |
JP2001232193A (en) | Methanol reforming catalyst and methanol reforming method |
Legal Events
Date | Code | Title | Description |
---|---|---|---|
AS | Assignment |
Owner name: HONDA GIKEN KOGYO KABUSHIKI KAISHA, JAPAN Free format text: ASSIGNMENT OF ASSIGNORS INTEREST;ASSIGNORS:NAKA, TAKAHIRO;SUMI, HIDEAKI;MATSUDA, KAZUHITO;AND OTHERS;REEL/FRAME:010410/0857 Effective date: 19991027 |
|
FPAY | Fee payment |
Year of fee payment: 4 |
|
REMI | Maintenance fee reminder mailed | ||
LAPS | Lapse for failure to pay maintenance fees | ||
STCH | Information on status: patent discontinuation |
Free format text: PATENT EXPIRED DUE TO NONPAYMENT OF MAINTENANCE FEES UNDER 37 CFR 1.362 |
|
FP | Lapsed due to failure to pay maintenance fee |
Effective date: 20111118 |